The objective of this proposed effort is to develop a laser welding technique for applications in urologic anastomotic repairs applicable to laparoscopic procedures in which conventional suturing techniques are difficult. The proposed project is designed to evaluate the strength of welds in a bladder augmentation procedure (enterocystoplasty) under feedback controlled laser power delivery mode to achieve desired preset surface temperature of the tissue favorable to reproducible weld integrity. Albumin solder will be used in the studies for enhanced weld strength. Due to the relatively thick bladder tissue (few mm), we will evaluate two laser wavelengths (l.32 micromoles and 1.9 micromoles) representing a large penetration depth (approximately 2.5mm) and a small penetration depth (approximately 0.1mm) in tissue respectively resulting in full thickness or partial thickness welds which may affect the repair process. Although partial thickness welds may have lower acute strengths, they may lead to better long term outcome due to reduced lamina propria damage. Phase 1 studies will concentrate on determining the optimal tissue temperature at which the acute weld strengths is the highest for the two lasers with differing optical tissue absorption and penetration properties. Phase Il studies will evaluate the chronic healing characteristics of welds made at the optimal tissue temperature for the two characteristic laser wavelengths. In addition, a laparoscopic delivery system will be designed and developed with temperature sensing and close- looped laser bower delivery compatible with a variety of laser sources, particularly compact diode laser, to accommodate various tissue thicknesses. This will broaden the application to many urological repair procedures. PROPOSED COMMERCIAL APPLICATION: The laser welder will be useful for various laparoscopically application that currently requires conventional suture tying. Our initial application is for bladder augmentation which involves approximately 6,000 to 7,000 cases a year. However, such a laparoscopic instrument has a potential of being useful in several hundred thousands of procedures a year.